1. Field of the Invention
The present invention relates to handling a wind powerplant's rotor hub or its rotor, using a hoist, in particular for erecting a wind powerplant or for assembling/dismantling a rotor to/from a wind powerplant. Moreover, the present invention relates also to a mechanism used to handle a wind powerplant's hub, hereafter hub, or its rotor, especially for erecting a wind powerplant or for assembling/disassembling a wind powerplant's rotor to or from it. The present invention again concerns using a tilting mechanism when erecting/disassembling a wind powerplant.
2. Description of Related Art
A large number of steps must be accomplished to erect a wind powerplant. Once its erection site has been made ready, various components of the wind powerplant are moved to its erection site. For example, several tower segments are assembled to each other to constitute one tower during erection, whereupon a crane deposits a nacelle on the tower and affixes it to said tower's top side. Next the rotor—which consists of a hub bearing rotor blades—is assembled and is deposited by a main crane plus an accessory crane on a rotor shaft at the nacelle. Alternatively, the hub first would be mounted on the rotor shaft, as a result of which, then using cranes or other accessory means, the rotor blades are affixed to the rotor's flange connections.
The rotors of present-day wind powerplants of the 5-6 MW class are heavy and their diameters are substantial. For example, the rotor diameter of the wind powerplant of the 5 M design made by the applicant is about 126 m. Assembling a rotor by mounting its rotor blades to a hub on the ground requires a large area that must be free of obstacles and be both plane and stable. For example, a clear assembly area of more than 5,000 m2 is required for a rotor diameter of 100 m.
Also, much labor is required in raising a rotor that was assembled on the ground, as appropriate rotation is required once it is raised in the air. For example, when assembling a rotor designed for applicant's 5M powerplant, two cranes plus (passive) hoists are used which partly engage the outer rotor vane zone and which, following rotor assembly, must be removed in a cumbersome and expensive manner.